The present invention relates generally to media sharing and management, and more specifically, to delegating or transferring one device's access to resources to one or more access devices.
Resources in the form of digital data are compatible across various devices such as audio players, computers, and portable media players. For example, resources such as an MP3 file may be listened to using a portable MP3 player, as well as a personal computer, a home resource server or a Personal Digital Assistant (PDA). With the convergence of the devices, people are presented with an increasing number of access devices from which the resources may be accessed. Therefore, more and more people use different devices in the same or different places to access the same resource.
Accessing the same resources on multiple devices, however, poses various issues. One of the issues is that it is inconvenient to transfer resources between devices. To access the same resource, the resources must be transmitted from an originating device to a destination device. Transmitting the resource between devices may take much time or bandwidth, and cause inconvenience to the users.
Another issue is imposing restrictions to the shared resources. The access to the resources may be restricted for commercial reason as well as privacy or security reasons. An example of restricting access for commercial reasons is digital rights management (DRM) technology. The DRM technology is used by publishers or copyright owners to control access to or usage of the resources. The DRM schemes often restrict sharing of resources between multiple users or across multiple devices. Moreover, some DRM schemes are not compatible with other DRM schemes. Therefore, if one form of a resource is subject to one DRM scheme for one device and another form of the same resource is subject to another DRM scheme for another device, the two forms of the resource must be individually purchased to access the resource on two separate devices.
An example of restricting access to resources for privacy reasons is medical records. The medical records are very valuable and useful if shared by appropriate medical personnel. On the other hand, access to the medical records must be restricted to preserve the privacy of the patients.
Another issue in sharing access to the resources across multiple devices is that it concentrates much of the communication traffic on the originating device. For example, if the user wants to share the same resource across several devices, the whole resource must be transmitted from the originating device to the several devices. The problem is exacerbated if the number of shared resources is increased. The data that must be transmitted from the originating device to the devices increases in proportion to the number of resources shared.
There is also the issue of differing capabilities of different devices. Each device may have different hardware or software configuration. As a result, each device may have different capabilities. For example, a standard television is capable of displaying images having 480 lines whereas a high-definition television is capable of displaying images having 1080 lines. Because of the different capabilities, the formats of the resources that may be accessed from different devices may differ. For example, a movie clip encoded for a high-definition television may not be displayable on a standard-definition television. Moreover, the resource may be optimized differently for devices having different capabilities.